Two common disorders, torticollis and positional plagiocephaly, involve an infant persistently maintaining a particular head position with respect to rotation about the infant's cranial-caudal axis. Both conditions therefore cause a particular region of the infant's head to be persistently in contact with the lying or reclining surface; this region of the head is hereby defined as the habitual contact region. Constant pressure on a habitual contact region due to the pull of gravity may lead to irregular bone development.
Torticollis refers to a condition involving imbalanced neck musculature whereby an infant is predisposed to have their head turned to one specific side as a result of tighter musculature on one side of the neck with respect to the opposite side. Positional plagiocephaly is a condition where the bones of the infant's cranium grow abnormally due to prolonged pressure on a habitual contact region, causing a flat spot to develop at that region. A flat spot often occurs at a posterior-lateral aspect of the head or the posterior-central aspect of the head.
Because torticollis predisposes the head to be turned in one direction, creating a habitual contact region, it can lead to posterior-lateral positional plagiocephaly. Likewise, a flat region present on a posterior-lateral aspect of the infant's head creates a stable base for the infant's head and consequently promotes greater periods of unilateral head and neck rotation. A sequelae of prolonged periods of unilateral neck rotation is imbalanced neck musculature; thus plagiocephaly may lead to torticollis or reinforce a pre-existing torticollis. Because of the close association between the two conditions they often coexist.
Positional plagiocephaly and torticollis can range from very mild to very severe; more severe or prolonged conditions may lead to structural abnormalities in the cervical spine as the spine does not develop throughout a normal range of motion. As well, if the conditions are not treated, craniofacial dysplasia including facial deformities, ear discrepancies and temporomandibular joint problems may develop. Structural abnormalities may lead to functional deficits and or cosmetic concerns. Plagiocephaly is more likely to develop in the first few month of life as the cranium is generally more pliable at this time. This is especially the case if a flat region was present at birth, as an infant's head tends to settle on the flat region; subsequently, more time is spent with pressure on the flat region. This may be considered a self-perpetuating plagiocephaly.
There are several variables that affect an infant's preference to have their head turned toward the left or right: individual factors such as muscle tone, head shape, tissue length, and cutaneous sensitivity; and external factors such as the sleeping surface, visually interesting objects or people, and sounds, especially a parent's voice. If the fine balance is shifted in either direction the infant will tend to favor having his or her head turned toward that particular side. Conversely, the infant may develop a preference to maintain the head in a straight forward position. In this position the habitual contact region is at the posterior-central aspect of the infant's head. This often leads to a flat region over the posterior-central aspect of the infant's head.
Sudden Infant Death Syndrome and the American Academy of Pediatrics:
Rates of positional plagiocephaly have increased over the last decade after the American Academy of Pediatrics (AAP) made the recommendation to place infants in a supine position (on their backs) to sleep in order to reduce incidences of Sudden Infant Death Syndrome (SIDS). The present invention addresses the latest AAP recommendations concerning SIDS and positional plagiocephaly. These recommendations are discussed in more detail below.
Infants should continue to be placed to sleep in a supine position. This recommendation has been very successful in decreasing incidences of SIDS and is now considered the standard of care. However, infants sleeping supine has subsequently lead to increased incidences of positional plagiocephaly.
Infants should no longer be placed in a side lying position as they tend to roll into a more dangerous prone (on the belly) position.
Objects such as pillows, stuffed animals, and quilts should not be placed in the crib. Wedges and infant positioners should not be used. Sleeping clothing should be considered as an alternative to placing quilts in the crib but infants should be lightly dressed to prevent overheating.
To prevent positional plagiocephaly an infant's head position should be periodically adjusted. Infants should also not be left in reclined positions for prolonged periods of time such as in car seats or strollers as pressure on the back of the head in a reclined position can also contribute to positional plagiocephaly.
There is no evidence to suggest that infants should be repositioned if they are able to comfortably change their own position. It should be appreciated that any method that restricts an infant from rolling to a prone position may also restrict the infant from comfortably re-establishing a safer supine position.
Commercial devices designed to reduce the risk of SIDS should be avoided as none have been sufficiently tested to prove efficacy or safety.
Infants who are accustomed to sleeping on their backs are up to 18 times more likely to die from SIDS when inadvertently placed prone to sleep. This most often occurs under the care of an alternate caregiver. Therefore, it is recommended that infants always be placed to sleep supine, unless otherwise instructed by a medical doctor.
Sensory Integration:
Sensory integration was defined by Jean Ayres (2005) as “the organization of sensations for use.” Infants use sensory information gained through their senses to make sense of their world and to determine how they are interacting with it. Sensory information is gathered through the five common senses: vision, hearing, olfaction, taste, and touch; and through an internal sensory system that detects the pull of gravity, body position and movement. An infant processes all the information received by his or her senses, typically unconsciously; analyses and organizes the information; then makes an appropriate response, such as moving a limb or turning his or her head.
Infant Growth and Development:
Infants learn by exploring their body, their environment and the interactions between their body and the environment. If an infant can only interact with a limited part of their body and environment it may adversely affect learning, cognition, balance, and motor development. Similar adverse affects have occurred as a result of prolonged movement restriction, such as in cases of child neglect.
Jean Piaget (1896-1980), the pioneer of child cognitive development, described four stages of development cognitive development. Infants are at the primary, sensorimotor stage. In this first stage infants must experience and learn about the world through their senses and through movement. An infant's notion of causality emerges gradually by learning that they can have an effect on the world around them. An infant's ability to make adjustments to his or her own surroundings is critical to proper development and also provides them with a sense of being able to influence their environment. Unfortunately, several therapeutic devices in the past have required the parent, guardian, or healthcare provider to impose their own will on the child, to restrict their movement and to restrict their interactions with the environment.
The supine position has been implicated as the cause of increased incidences of positional plagiocephaly; however, it should be made clear that many infants sleep supine and still develop naturally shaped heads. Infants who freely move their heads while in supine position tend to develop naturally shaped craniums. It is a constant pressure to one region of the infant's skull, the habitual contact region, as a result of a maintained head position, that leads to positional plagiocephaly.